Small bore pipe is used to transport fluids in a wide range of applications in both industrial and domestic environments, including for example the supply and distribution of low pressure gas, in the transportation of toxic fluids and/or the supply and distribution of water, such as potable water.
During the installation, working life or decommissioning of such pipe, it may be necessary to isolate a section of the pipe for repair, replacement and/or to permit an intervention into the pipe to be carried out.
However, the isolation of, and intervention into, small bore pipe provides a number of challenges to conventional isolation and intervention equipment and techniques. For example, conventional equipment and techniques are typically complex and require specialist contractors to install and operate. Moreover, conventional isolation and intervention equipment and techniques used in low pressure gas supply and distribution suffer from the drawback that they permit escape of gas to atmosphere, posing a significant risk to personnel and the environment; the alternative being the complete shutdown of operating equipment at significant expense to the operator. Equipment and techniques have been proposed for use in low pressure water applications. However, these fail to provide sufficient pressure integrity to permit their use in gas supply and distribution applications. Such equipment and techniques also require that isolation equipment in maintained in-situ after intervention operations have been completed and so do not comply with safety codes for gas or other hydrocarbon systems.